jmeiners

I have an issue with my car and wanted to see if anyone else is experiencing something similar.

When I am driving around and am "coasting" (not on the gas, not off the gas while maintaining speed) the engine will feel like something is dragging (like someone through an anchor out the back). The rpms don't change, but it will feel like I downshifted. This will go on for about half a second and then it will go back to normal. In bad cases, it will go back and forth several times in a 3 second span. It is very noticeable in the lower gears (can someone say whiplash?), and only mildly annoying the the higher gears. It started at about 13000 miles and has been going on for about 10 months.

I took it to the dealer and the foreman told me that it was the valve timing changing that was dragging on the car. They reset the computer but nothing changed. They then called the allmighty answer place (wherever that is) and came up with "the ecu needs to be re-programmed and they are working on the fix". That was 10 months ago and still no word. I HATE driving the car in this condition. It is HORRIBLE in traffic where you are always "coasting" around before you put the brakes on at the next slowdown. I would rather (and do) drive my 18 year old pickup.

Anybody else experience the same thing and/or gotten a fix? Any info would be appreciated. Thanks.

engifineer

Wow... good foreman there. I have never heard of anyone having this issue before on the tC, so I doubt anyone is "working on a fix" by writing new programming, since other tCs dont have this issue. Now, if this were not a VVT-i setup I would say it was a faulty EGR valve or solenoid, but the tC uses the VVT-i setup to provide the EGR function through valve timing (A faulty EGR valve can act like a vacuum leak at cruising speed). In any case, I would make him explain to you who is working on this "fix" and why they would re-write code for ONE car. If the valve timing is indeed changing randomly, then they should fix it by replacing your ECU or correcting whatever is making the ECU make incorrect changes. If they need to reflash your ECU to factory specs, then they should have had that fixed a long time ago, not 10 months later.

KINGxOFxSKA

Hmmm... haven't heard of that problem until today. Just keep bugging your dealership or go to another one until they re-program it for you. Doesn't seem like it would be THAT hard for them to do or figure out.

ryan9800

What type of gas are you using? What brand? What gear is this happening in? What speed? Auto or manual? If auto could be a overdrive problem???!!! Let us know...

toyota_scion_tc

Is there a CEL on? If so read the code and see what it is. What weight oil are you using? In newer cars with vvti or vtec if you use the wrong weight oil it will mess it up because the oil pressure will not be as high with the right volume as it needs.

jmeiners

No CEL on.

Gas is usually shell, chevron, or 76. Regular unleaded. It happens in all gears, but only when "feathering" the gas. If I am off the gas it doesn't happen. It happens in that magic 2000 - 3000 rpm range in all gears (right where I have been told that the vvti starts). Manual transmission.

The last time I had it in, they had it for about 2 weeks waiting on an answer from somewhere. Then came back with the re-programming thing. The dealer said that he drove a couple of used TCs on the lot and they did it too, one worse than mine (hard to believe). Then I looked on here and no one else was complaining. Kinda strange.

ryan9800

LEMON! Somthings got to be going on?

engifineer

How would that be a lemon? Doesnt even fit into the category. He just has one issue and it sounds like the dealer is just avoiding fixing it

Take it to another dealer. VVTi is a constantly variable system, it is nothing like VTEC in any way really when you get down to it.

Go drive another one. Mine and the couple I have driven do nothing of the sort. Mine drives just like any car really. I honestly have no idea what your dealer is talking about. But to be sure, all you have to do is go test drive another one.

StealthScion

Not on the gas, not off the gas?? WTF? How can you be neither on or off the gas? Either your foot is pushing down on the throttle pedal or it isn't. Which one? Do you mean engine braking (ie. letting off the throttle pedal while coasting in gear)? if you are engine braking, yes, the motor will buck a little bit as you get on/off the throttle.

Not surprised that the dealership "foreman" gave you a load of BS. There is no freaking way the ECU would need to be reprogrammed. Thats total BS. Ie. They don't know what the heck is going on (or nothing is wrong, its in your head) and they're buying time until A) something breaks (then they'll know what was wrong B) Other tc's start having the same issue and scion investigates C) you forget about it.

I've found that except for the TSBs (and even those in some cases) the toyota/scion techs have no more knowledge about these cars than we do.

JDMonkiTC

ive experienced it, it only happened twice though. i was heading up a hill and my engine did something different, it sounded like the rpms were going back and forth for about 10 seconds then but my gauge showed no change. and i could hear it pretty loud since i have the hks axel back. it was strange. it happened twice. but after that, never happened again, so i just left it alone

htowntc

im surprised noone has said throttle positioning sensor yet,

semms to ALWAYS be the TPS TPS TPS

TrueSlide

Sounds like deceleration to me... you can't have your foot off the gas and maintain speed. Unless you're in neutral, but you will still decelerate.

bcnu_702

Well I do it all the time, but i'm in cruise control

trdsparks

WOW!



I would take it to the dealership and have someone there ride with you so they can see exactly what is going on. Then leave the car there and have them fix it. Do it now and get it over with that's what your warranty is there for. Don't wait any longer.

TrueSlide

I think what you're experiencing in the deceleration of the engine, and the half second that is concerning you is the motor adjusting to coasting while not receiving any throttle.

(And to note... since it seems the tech you talked to spat out some B.S. IMO I would call a couple of dealerships and tell them the same exact story and see what they all say. Try like 4. I bet you everyone of them will either be stumped, or give you a different reason, probably because they've never heard of it and it's nothing really. But... get a second and third opinion. Always. Even if you bring it to all the dealerships they probably wont figure it out. Take a tech for a ride so he know's what you're talking about...)

toyfixer

hello everyone. i am new to this forum so to give u a little background i am a toyota master tech at a toyota/scion dealer in milwaukee. the "allmighty answer place" is a tech support department that toyota has in california that techs can call when they run into a strange problem that cant easily be diagnosed. they keep records of things like that so they know if something is a problem or just an individual incident. i have talked to them several times about different things and have been told just what u were told. that they know its a problem and they're working on a fix. they meaning toyota. it is not uncommon for an ecu to be re-programmed. there is actually a recall out right now on highlanders and rav4s for just that, and several tsb's for different vehicles. the problem u described could in fact be just that. if the cam timing is changing when it shouldnt it would affect the tone of the engine but maybe not affect rpm. the ecu controls this. so i guess i would keep checking with the dealer and make sure they stay on top of it. i'm not saying all techs and dealers are always right, but it sounds possible in this case. i hope my insight helps

TheStig

I have a problem that is somewhat similar to this, I think.

It's worse after school, when my cars been sitting outside in like 20 degree weather. Basically when I drive out of school over speedbumps and stuff like that in 1st or 2nd gear the car is EXTREMLY jumpy. it's like I'm constantly jumping on and off the throtle.

On top of that it's difficult to get the car into gear until it starts to warm up a bit. I assume that it's cause the trasmission fluid is really thick and sludgy because it's been sitting outside for like 7 hours. The problem usually alieviates itself after a couple of minutes and I don't worry about it.

TrueSlide

^ you said it... the car needs to warm up. It's HIGHLY recommended to let the car warm up. Let it sit for a minute or two, then go ahead and give it a little gas. Don't rev high tho... Everything needs to warm up thats all... if you live in that cold of weather you should really warm it up